A detailed study of the life history of messenger RNAs in mammalian cell lines is in progress. Kinetic analyses of the rate of synthesis and intra-nuclear transit time are being done, with emphasis on globin mRNA in Friend leukemia cells. Proteins associated with mRNA in the nucleus and cytoplasm are being analyzed by gel electrophoresis. Methods for high-resolution analysis of chromosomal protein populations by two-dimensional gel electrophoresis are being developed further. Preliminary attempts to identify individual proteins from cytoplasm and/or nucleus of human cells, and to assign them standard coordinates in the two-dimensional gel patterns, are in progress. BIBLIOGRAPHIC REFERENCES: Peterson, J.L. and McConkey, E.H. 1976. Nonhistone chromosomal proteins from HeLa cells. A survey by high-resolution, two-dimensional electrophoresis. J. Biol. Chem., 251:548-554. Peterson, J.L. and McConkey, E.H. 1976. Proteins of Friend leukemia cells. Comparison of hemoglobin-synthesizing and noninduced populations. J. Biol. Chem., 251:555-558.